It is known to make vehicle dashboard crossbeams from several sections assembled to each other. Such a structure makes it possible to adapt the dashboard crossbeam to its environment by selecting sections that are adapted, in terms of materials, geometry, mechanical properties, etc., to the zone in which those sections are designed to extend in the dashboard. Thus, the section designed to support the steering column of the vehicle will for example be more rigid than an adjacent section designed for another function. The first section will therefore be made from substantially heavier and bulkier appropriate materials than the second section. Such a structure thereby makes it possible to reduce the mass and bulk of the crossbeam by providing light and thin sections in areas where the rigidity stresses are lower.
It is known to assemble the sections together by laser or electric arc welding (Mag welding). However, such methods for assembling the sections are not satisfactory. In fact, it is difficult and expensive to produce continuous weld lines extending over the entire periphery of the sections in their junction region with another section. The fastening is therefore only done by weld points, which reduces the rigidity of the crossbeam and junction regions and decreases the performance of the crossbeam. These methods are not adapted to sections having small wall thicknesses, for example smaller than 1.2 mm, which limits the mass savings that may be obtained by reducing the thickness of the sections. Furthermore, these methods cause a significant increase in the temperature of the materials used to produce the sections when the sections are welded together. Such an increase may cause deformations of the sections, which leads to defects in the desired geometry of the crossbeam, as well as degradation of the mechanical properties of the crossbeam. Lastly, laser welding or Mag welding causes molten metal projections, which are dangerous for the operators performing the welding or located around the crossbeam being assembled.